


Ethical Ponyplay When Your Girlfriend Is Your Mount

by Xekstrin



Category: Fire Emblem: Fuukasetsugetsu | Fire Emblem: Three Houses
Genre: F/F, explicit monsterfucking
Language: English
Status: Completed
Published: 2020-03-15
Updated: 2020-03-15
Packaged: 2021-02-28 17:33:33
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,064
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/23151007
Author URL: https://archiveofourown.org/users/Xekstrin/pseuds/Xekstrin
Summary: Marianne turns into a monster when her emotions run high. The only one who can soothe her down is her girlfriend Hilda, and of course Byleth decides this means Hilda is going to be a mounted unit and ride Marianne into battle to lay their enemies low with fang and claw.This understandably puts a damper on their relationship.Thankfully, Hilda is a trooper and with the creative use of a muzzle and constant praise kink, we can safely be intimate again. Hurrah! Hurrah for Hilda! She really is the smartest unit on the battlefield.
Relationships: Marianne von Edmund/Hilda Valentine Goneril
Comments: 17
Kudos: 214





	Ethical Ponyplay When Your Girlfriend Is Your Mount

Her lungs burned. Every gasp came out in heady little stitches as her legs pumped and Hilda Valentine Goneril ran for her life. Sliding and slipping down a patch of mud, she spared a single prayer for her skirts as yesterday's rain meant she couldn't get a good purchase on any of the peat-covered hills. Mist covered the fen, thicker than blood, and it clung to her skin in beads, dripping down with the sweat on her forehead.

Skidding to a halt, she crouched in the shelter of a tree struck by lightning. Her eyes caught a funnel of darkness and she squeezed into the crevice without thinking. The smallest, most primal part of her brain screamed _dark! safe! hide!_

It was a mistake.

Soon she heard the breathing, then the stench of blood from a dozen murdered soldiers. Nobody she knew, thankfully. She and Marianne had been surrounded by a group of raiders there to pick off any survivors after the battle, and that was when it happened.

That was when the Beast came out.

She heard the steady, low hiss of a tail being dragged through dirt. And every footstep caused the earth to rumble, or maybe that was just her adrenaline-soaked fantasy. Hilda shivered in her shelter, waiting for the massive footsteps to pass.

And instead a hand, big enough to grab her by the waist and touch thumb to forefinger, whipped into her hiding space and dragged her free.

Hilda struck back like the cornered prey animal she was, not an ounce of hesitation. "Fuck you!" she hissed, stabbing it over and over again with the knife she kept strapped to her garters. It'd been a gift from her older brother and she jammed it hilt deep, piercing flesh, driving it into the claws that grabbed her, into a furred chest.

Instinct. She didn't know where she found the energy to fight back. In a shower of splintering wood and mist, Hilda swung her knife and sliced open the Beast's hand. It didn't release her or even flinch, only squeezed her harder until she screamed and dropped the knife.

Bad instinct. She really should have trained better with that thing.

The Beast was something out of her nightmares, a great scarred thing covered in the weapons of everyone who failed to kill it. Blood coursed down scaled flesh, fresh blood the color of cornflowers. Thoughtlessly, it snapped off a javelin buried in its shoulder and tossed it aside, breathing hard, two jets of mist from massive nostrils. 

And an eye, a great eye the size of a saucer, staring at her. A snout so long it could only stare at her with that one eye, the whites so wide she thought she might drown in them.

"Marianne," Hilda whimpered the grip around her neck tightened, "Please. It's me! It's Hilda!"

The Beast responded with a roar, spittle flying onto her face. 

Then it petered out, turning into a rumble, and then a low purr. 

Slowly, little by little, Marianne's grip on her loosened. 

And a deep voice spoke. 

"Hilda?" the Beast said.

"Yeah, honey," Hilda said, soothing her down. She scrabbled at the paw around her throat, trying to pry the Beast's fist open. "It's only me. Just relax. We can just relax and take it easy, right? Doesn't that sound nice?"

There wasn't a person on the planet she couldn't charm, bribe, or manipulate. Her words were her most powerful weapon. But they were nothing but a feeble wheeze, nothing except a dying breath. Later on Manuela told her she had a concussion. That was the only explanation for what she did next, as she reverted back to the only defense she could think of.

Flattery.

"That's my pretty girl," Hilda said, "You're so beautiful like this. I had no idea."

A violent shudder rolled through the Beast's body. The Beast stood twice as tall as the average man, her sinuous, draconic body easily able to lope along on all fours or stand up on two hind legs. Her belly shone in the pre-dawn light, scales glittering and shining like beetle shells or turquoise, and her back was covered in long, wavy fur. She really was quite pretty, in a grotesque way.

But she let go of Hilda, bit by bit, until she was standing on her own two feet and could breathe again. 

"That's it, baby. That's my girl." Hilda gasped for breath as she patted Marianne's massive flank. She wobbled, her knees unsteady. "That's my beautiful girl."

A low moan sounded out, like cattle lowing in the pasture. It would have been funny if it weren't so sad. Marianne covered her horned head with two massive hands, spindly fingers splayed over her snout. All Hilda could see was that big brown eye again, wide with terror as Marianne groaned. 

"What did I do?" Marianne said, looking down at her blood-stained claws, tears streaming down her snout. She began ripping out the weapons in her hide, swords and spears and arrows, wincing and sniffling at each one. "Wh-what did I do?"

Stunned, with her whole body throbbing with pain, Hilda found she could only stare at the quietly weeping monster. And a single thought rose up in her mind, _Wow, Marianne. Even like this you're kind of pathetic._

"Nothing bad, I promise." Hilda was in full ass-kissing mode, trying to soothe her down. She noticed Marianne missed a spot and warned her before trying to take another arrow out. "You just gave me a nasty shock, that's all. I didn't know you could, uh, change like this."

Marianne was babbling something now, an apology, or an explanation, and Hilda nodded and made soft crooning listening noises at the appropriate times. She got a lot of practice doing that around Lorenz— around 90% of the male population if she was going to be honest. None of the wounds were deep enough to kill, but Marianne refused to let Hilda try and dress them, so she figured there was only one other option. Taking Marianne's massive hand, she guided her back towards home base, limping with every step.

That was how Byleth found them, and after making sure the two women weren't injured, their first instinct was to say, "This could be useful."

  
  


People called Hilda beastmaster which publicly she abhorred but privately quite liked. In between the group's mages and Hilda's insistence on fashion as well as function, they were able to create a harness that shifted alongside Marianne. No one else could soothe Marianne when she was in that state, and she was just as likely to hurt her allies as her enemies—

Unless, of course, Hilda was there to hold the reins. Literally.

"Thanks a _lot_ Marianne," she grumbled, not for the first time as they trotted towards the front lines. "Now I have an extra responsibility. Babysitting you on the battlefield is not my idea of a good time." 

"I'm sorry," Marianne said, her voice deep and gravelly and unfamiliar. She zipped along faster than any mount Hilda had ever ridden, and on top of that, her gait was completely alien. Neither horse nor wyvern could quite compare to clinging to Marianne's back as she mowed through the enemy ranks in a fit of bloodlust. "But the Professor says they really need us today."

"Yeah, yeah, I know," Hilda said, and pulled on Marianne's reins to direct her further into enemy territory. 

The best part—

The worst part— 

The _best_ part was right afterwards. Marianne needed a place to recover and cool down, and couldn't be around people. It took a lot of trial and error but eventually they discovered that her bloodlust only extended to humans. In this shape, as in her everyday life, Marianne vastly preferred being around animals. So she and Hilda would settle down in an empty stall right next to Dorte, who peeked curiously over the wooden barrier, unafraid while Marianne talked to him.

It was an unexpected relief. If animals had been afraid of Marianne as well as people, Hilda wasn't sure she'd be able to cope.

The stables smell didn't bother her after a while, and their area was always kept clean anyway. And while Hilda had Marianne as an excuse, she could loaf around all day in there. They always kept a few books on hand, and she spent more than a few afternoons reclined with her head on Marianne's warm stomach, and played with her scales until they softened and her girlfriend was back to normal, breathing hard and covered in sweat. 

So the best part was right afterwards, when Marianne was naked except for the leather harness. Hilda rubbed her down like a horse after a long ride, and her girlfriend was limp in her hands and completely drained. Her pretty brown eyes fluttered with exhaustion, like she might fall asleep right there.

Shaking out the washcloth, Hilda marveled at the loose scales that fluttered free. Aquamarine and turquoise and sapphires didn't compare. They really were _so_ beautiful, she didn't need to lie about that. Not that Marianne needed to know what was the lie and what was the truth. Marianne also didn't need to know that Hilda kept the best scales for her personal collection. She had a box full of Marianne's body parts and she told herself it was payment for keeping her girlfriend from murdering their classmates.

The problem with having an exceptionally docile and useless girlfriend was that Marianne actually wasn't either of those things, when push came to shove. It should have been impossible to underestimate her after how this all started, but familiarity breeds contempt, as they say.

Hilda thought Marianne was _tame_. 

That's how Hilda found herself with a half-shifted Beast, gum-deep in her forearm, and Marianne's pretty eyes were wide and feral and unseeing as she growled and bit deeper.

"Marianne," Hilda said, way more calm than she felt as blood began to drip on the stable floors. Marianne should have cooled down by now, but it looked like they might need more time alone before that was the case. The scent of all this was going to start making the horses antsy, and Hilda didn't like the idea of explaining this to the Professor, so she decided to handle it on her own. "I need you to let me go. Okay, babe? This is an expensive shirt."

Marianne did let her go, eventually, and then patched her up while crying all over her expensive shirt and apologizing. Hilda bore it all with a curious emptiness. Like, she thought maybe she should have been afraid or upset but she wasn't. If anything, she was frustrated with herself.

She commissioned a muzzle for her next, to be used primarily outside the battlefield, during transport and cooldown. On the battlefield everyone on the friendly side already knew to give her mouth a wide berth. Outside it, Hilda was generally the only one at risk.

It didn't feel like a risk most days. It was just like, kind of annoying, you know. Everyone else, they finished fighting and got to pack up and have their trauma elsewhere, but Hilda had extra assignments after class, so to speak. Her and Marianne in their self-imposed detention, hanging around the horses and waiting for the twitching Beast to finally settle down and turn back into a human. 

Hilda made the mistake of complaining about it one too many times and Marianne finally snapped back, "Do you think I like this? Do you think I enjoy being treated like an animal? Like a hornet's nest waiting to erupt?" and, breathless, stood there on the verge of letting Hilda have more of her mind. Then the enormity of it overwhelmed her and she shivered like she was fly-bitten, the shadows under her eyes darker than ever.

"Poor Marianne," Hilda said, "It's rough, isn't it?"

Stiffly, "It is."

Marianne was already fully dressed. So Hilda began brushing her long hair, carefully pinning it up. As she did so, she spoke gently to her. After all, she was practiced at getting Marianne to calm down. When Marianne's hair was done Hilda pulled out a pocket mirror and showed it to her. "Look. Now you're all back to normal and we can go have dinner. Sound good?"

Marianne crumpled a little, eyes closing wearily. "It does. Can I treat you to tea in my room afterwards?"

"Hmm." Her eyes flashed. "You'd better. I have something good to show you tonight, too."

One positive discovery was that Hilda never got tired of hanging around Marianne. She thought being ordered to stick around each other would quickly drain the romance, but it actually forced them to be more considerate with each other. A little kinder. 

"You know when you first asked me out I just said yes because I was bored?" 

Well, a _little_ kinder.

Marianne's brows lifted, her voice dry. "You say the sweetest things."

"I'm serious." Lounging on her floor, Hilda munched on a delicately soft, sweet biscuit. "I was like, eh, why not. It'll be over in a week when Marianne gets tired of me or I get bored again."

"But you didn't get bored."

"No! I can't believe I ever thought I might. You're so cool and so funny when you really get going." Reaching over, she wormed her hand under Marianne's skirt. Stroking the inside of Marianne's thigh, she gave her girlfriend the most smoldering look she could muster. "I'm not sure when it happened but I'm kind of addicted to you now. Are you tired of me yet?"

Marianne shook her head. "No. Never." and Hilda was getting some pretty great vibes over the way she was looking at her. They were on the same horny page, until Marianne started cooling down, turning her gaze aside with a haunted expression. "I'm... sorry you have to be responsible for the worst of me."

"It's fine. Really." Even when Marianne lost control these days it never required more than a few sutures. Maybe a healing spell from Manuela and she was right as rain. Not even a scar. "I love you. _I'm_ sorry I stabbed you that first time you changed."

"You were scared, Hilda." Marianne's hands turned into two hard fists on her lap. "I was trying to kill you."

Getting bored with this line of conversation, Hilda decided to be more direct. She moved to straddle Marianne's lap, lacing their fingers together so Marianne couldn't make those angry hard fists anymore, and kissed her so she could stop apologizing. 

She made Marianne touch her, eager for release and the scorching hot tension of naked flesh on flesh. In times like this she felt like maybe she was the beast and Marianne was her tamer.

"You want this?" Hilda paused long enough to say, working through all of Marianne's layers to find her ready. She was hot and wet like after a fight, and Hilda just wanted to rub her down.

Marianne's expression flickered between eagerness and guilt, uncertain and ravenous. "I, uh—"

She stopped touching her, waiting. "It's a yes or no question, pretty girl."

No answer, then, which wasn't a great sign. Until Marianne muttered, "Do you really think I'm pretty?"

Hilda sat up straighter, spine rigid with excitement. "Yes! You're gorgeous. I'm so jealous. Like look at this." She unpinned Marianne's hair, which was kind of a shame because she spent so long making it look good. "Look at how long and shiny your hair is."

"Your hair is pretty, too," Marianne quietly countered, but Hilda wasn't having any of it.

"And your long, sexy legs. It's a shame you hide them away." Hilda patted them again for good measure. "And your—" she stopped. "This is a bad time to say your scales are pretty, too, isn't it. But it's true. It's like I've got a gem-encrusted girlfriend."

Getting Marianne to giggle was like a blessing from the Goddess. Doubly so when it was about that accursed other form she took, the one that caused them both so much stress. Taking that as a good sign, Hilda showed Marianne what she'd been working on.

"Don't get mad," she prefaced it.

"It doesn't bode well if you already have to caution me against anger," Marianne pointed out, but promised not to be mad anyway.

Hilda showed off the designs she was making with Marianne's scales. Nervously, she put on a set of earrings, and waited for the verdict. 

"You're weird, Hilda," Marianne finally said.

"Hey!" 

But it was hard to stay _too_ mad when Marianne started giggling, nervous at first, then uncontrollable. They started kissing each other again, in between Hilda admonishing her and Marianne hiccuping with laughter. It turned into a groan of need when Hilda fondled her breasts, quietly urging Marianne to touch her too.

"I've been on edge all day," she said, trying not to sound desperate. "Marianne, you don't know how beautiful you are. It drives me crazy, you're even—" Her girlish moan verged on a squeal when Marianne's long, slender fingers finally pushed up her skirt. "Oh, Goddess. Yes. Yeah. That's my girl. That's my pretty girl."

She shuffled higher onto Marianne's lap, pulling the other girl's head to her chest. Rocking onto her hand, she wove her fingers into silky blue hair, gripping her head and sighing with relief. Hilda wriggled out of her top, just enough to get Marianne's mouth on her breasts. 

"Yeah, I like that," she said, for an instant missing the reins because she wanted to direct Marianne's head everywhere she needed it. "Bite a little."

Marianne agreed with a growl. A _real_ growl, one that made them both pause. When Marianne sat back to stare at Hilda pleadingly, her mouth was twisted in an odd way, like she was holding a frog in there. 

When she spoke, her voice was strangely muffled. She gently moved Hilda off of her. 

Even though she tried to hide it behind one hand, Hilda easily saw past it all. Marianne's every word betrayed the mouthful of razor sharp teeth, all too big for her human jaws to house. 

"I think you should leave." Marianne looked ill.

Hilda had a duty to her classmates. She had a responsibility to look after Marianne when she was in danger of shifting. She had an obligation to look after the woman she loved. And she was so horny she would hump a pillow if it offered the promise of release.

"Do you think you could just wear your muzzle and fuck me anyway?" she suggested, too fast and a little breathless. "I'm not scared. I love you. That means I love you a little in the leather too." _Maybe I love you a lot in leather._

The desperate, hungry expression in Marianne's eyes let Hilda know she was close to convincing her. It would have been the smart and sober thing to talk this out when they both weren't breathing hot and hard. It would be the right thing to do. But they were both inching closer to each other and Hilda thought she might die if she had to be the responsible one, _again_ , when she was so much better at telling people what to do.

"Put it on," Hilda said, then again louder when Marianne started doing just that. "See? It's perfect cause I had it made special for you. It's comfy, isn't it?"

"This is strange," Marianne said, but not in a way that sounded like a complaint.

"It's not." Hilda grew impatient and started fastening it herself, caging Marianne's mouth. She saw strands of saliva slinging from tooth to jagged tooth and had to close her eyes for a second, getting control over herself. "You know I love your hands, anyway. Are you going to grow talons, too?"

"No. I mean, I don't think so..."

"Try really, really hard not to. Okay?" She stuck Marianne's fingers into her mouth even though she didn't need it. Standing chest to chest, she drew Marianne's wet fingers down between her legs. "Very good, Marianne. _Very_ good."

Her girlfriend made a breathy noise, somewhere softer than a whimper. And her fingers were so soft and so clever. It was like Marianne could read her mind and knew exactly how she needed to be touched. Of course that didn't stop Hilda from telling her in excruciating detail what she wanted. No one had ever accused her of being quiet.

"You're so good, Marianne. Keep touching me right there." She bit her lip and squirmed, bowing her head to rest against Marianne's shoulder. Marianne's hand worked faster, pulling her closer to release. "Just like that. I needed this soooooo bad. Even when I was riding you I just wanted to fuck you."

Marianne's hand stilled for a moment in confusion, and Hilda felt a thrill of fear go through her. She hadn't meant to say that part out loud.

Marianne said, "What?" and Hilda responded, too quickly, "What?" in the exact same tone.

And Marianne then softly said, "Oh," and Hilda wondered if she ought to jump out the window or let her girlfriend maul her to death, because an eternal abyss would be preferable to the awkward tension in the room right then.

Shrewd brown eyes worked over her, Marianne piecing it all together. Bearing it as stoically as she could, Hilda broke out into a cold sweat as that interminable silence stretched on and on. Then she tensed, gasping as Marianne's fingers circled her entrance again, slowly. 

"Like this?" Marianne asked, under her breath. 

She rested her hands on Marianne's chest to steady herself. Hilda gulped and nodded her head.

After a long, thoughtful moment, Marianne said, "Okay."

Marianne's fingers slipped up inside her. Lazy, shallow thrusts pulled her to the brink again, inch by inch. Hilda tried to stay patient, holding Marianne's gaze and trying to convey all her feelings across without words.

She ground her palm to Hilda's clit, forcing her to move faster. And Hilda threw her arms around Marianne's shoulders and rode her, bumping her face against the cage around Marianne's face once or twice when she forgot herself and tried to kiss her.

"Please— oh, please—" Hilda kept whimpering, her knees almost giving way when all the pleasure suddenly spiked, too soon and too fast. But Marianne kept her other arm tight around Hilda's waist, holding her upright as she fucked her through her orgasm. 

Clinging to Marianne for dear life, Hilda panted up at her, suffused with bliss. She even forgot to be embarrassed, feeling nothing but awe at the woman holding her. A faint slit had entered her pupils, her jaw too wide and too long, and Marianne's every breath rumbled with a purr. Hilda tested her strength, letting go even more until her knees were half bent and only the tips of her toes were touching the floor. 

"Oh, more, please," Hilda said, dizzy from need, from the realization that Marianne was half-transformed and yet still fully in control. She clenched around the fingers inside her, growing bigger and rougher with every passing second. She braced herself for pain, for a tear, something sharp where it didn't belong, but it never came. 

Instead Hilda squirmed as those fingers stretched her out. They grew inside her, harder, firmer, and Marianne's movements slowed to compensate. Hypersensitive to every shift and twitch inside her, Hilda groaned helplessly. Then Marianne arched her wrist, rough scales braced over Hilda's clit, and Hilda came again with the Beast inside her.

Something that never changed about Marianne were her big brown eyes. If anything, they just got bigger, blazing with confidence and satisfaction at how Hilda fit into her palms. She broke her over and over again, delighted at this new aspect of her transformations.

"You're so amazing." Hilda was left wordless, for once. Two fistfuls of steel blue fur, and her body shaking and covered in sweat. She could only say that, over and over again. "You're so amazing, I love you. You're so fucking amazing, Marianne."

When later prompted by Byleth what happened to make Marianne so much more manageable during her transformations, she stammered through a response until Hilda helpfully stepped in, taking charge again while Marianne hovered nervously behind her.

Obviously, as Hilda explained, it was just the result of a lot more "hands-on" training.

Obviously.


End file.
